1. Field of the Invention
The present invention relates to a method for suppressing formation of deposits on a fuel injector and a device for injecting fuel.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 62-103456 discloses a fuel injector for an internal combustion engine, having a radiating member with a high thermal conductivity, to prevent the temperature of the nozzle holder from being higher, to thereby prevent the evaporation of fuel in the nozzle holder. In general, the nozzle holder should have a durability to ensure the precise control of the fuel amount to be injected, and thus should be formed of a material with a low thermal conductivity. Therefore, this fuel injector is additionally provided with the radiating member with a high thermal conductivity to keep the temperature of the nozzle holder lower. Thus, the actual amount of fuel injected is prevented from being deviated from the target amount.
Japanese Unexamined Utility Model Publication No. 63-151970 also discloses a fuel injector for an internal combustion engine, having a radiating member with a high thermal conductivity surrounding the nozzle, and a coating with an oil repellent covering the tip of the fuel injector. If the temperature of the nozzle holder around the nozzle becomes higher, the fuel remaining on the inner surface of the nozzle after the fuel injection may be oxidized and may form the deposits. Such deposits will reduce the amount of fuel injected. To prevent this, in this fuel injector, the radiating member is provided to shield the nozzle from the radiant heat from the engine, and the coating is provided to allow the remaining fuel on the inner surface of the nozzle leaving away therefrom easily.
However, if the fuel injector is arranged in the combustion chamber of the engine to inject fuel directly into the cylinder, the radiating member or the coating as mentioned above does not suppress the temperature rise of the nozzle sufficiently, and do not suppress the formation of the deposits sufficiently.